Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Disks encircling hypergiant stars may spawn planets in inhospitable environment

10.02.2006


RIT astronomer uses NASA’s Spitzer Space Telescope to study massive stars


This illustration compares the size of a gargantuan star and its surrounding dusty disk (top) to that of our solar system.



The discovery of dusty disks--the building blocks of planets--around two of the most massive stars known suggests that planets might form and survive in surprisingly hostile environments.

The discovery was made through NASA’s Spitzer Space Telescope observations of two hypergiant stars in the Large Magellanic Cloud--the Milky Way’s nearest neighboring galaxy--by a team led by Joel Kastner, a professor at Rochester Institute of Technology’s Chester F. Carlson Center for Imaging Science. His team’s findings will appear in the Feb. 10 issue of Astrophysical Journal Letters.


So far, searches for planets outside the solar system have been restricted to sun-like stars. All of these stars are older, dimmer and cooler objects than hypergiants, which are extraordinarily large and luminous but shorter-lived by billions of years.

Kastner and his team used infrared spectra obtained by Spitzer to study a population of dying stars. They added a new direction to their project when Spitzer’s infrared spectrograph revealed unexpected information. Spitzer’s sensitive spectrometer, which breaks down infrared radiation into component wavelengths as a prism splits visible light into a rainbow, indicated that a third of the stars in the population thought to be in decline--including two massive and exceedingly luminous hypergiants--were actually younger stars in varying stages of development.

The curious spectra of these two hypergiants (R126 and R66)--with one star being 70 times bigger than the sun--led Kastner to reexamine the stars’ classifications as dying. The shape of the spectra, or the amount of light from different wavelengths, is characteristic of flattened disks of dust orbiting the stars.

The two stars’ similar spectra differ in detail, with one encircled by dust in crystalline form, the other by more shapeless, amorphous dust grains. This expands the range of known conditions under which complex dust grains and molecules can form and persist around stars, Kastner says.

Kastner describes the complex mixture of dust detected around the stars as the "tip of the iceberg," probably signaling that the disks of debris surrounding the stars are similar to the solar system’s Kuiper Belt, a vast, distant collection of comet- and even Pluto-like objects. "To explain the very strong infrared radiation we detected, the stars we observed would have to host especially large Kuiper belts," he says.

He adds: "If Kuiper belts are the smoking guns of planetary formation around stars, it seems that these stars, as massive as they are, may be forming planets."

Hypergiants are only a few million years old and have a relatively short lifespan as far as stars go, considering the billions of years it will take the sun to expire.

"These planetary systems, if they do form and exist, are short lived because these massive stars explode as supernovae," Kastner says. "So it’s amazing that the raw material for planets could be found in such a hostile environment."

Kastner’s study highlights only two of more than a dozen or so known examples of very massive stars in the Large Magellanic Cloud that are bright infrared sources. The next phase of the study will use new Spitzer spectra of the additional hypergiant stars to determine how many more are encircled by dusty disks and why only some of these disks contain crystalline dust grains.

"We’ve discovered a new class of object, and we need to use Spitzer to measure the infrared spectra of a lot more of these objects to learn how unique they really are," Kastner says.

Kastner’s team includes Catherine Buchanan from RIT and B. Sargent and W.J. Forrest from the University of Rochester.

Susan Gawlowicz | EurekAlert!
Further information:
http://www.rit.edu

More articles from Physics and Astronomy:

nachricht Taking a spin on plasma space tornadoes with NASA observations
20.11.2017 | NASA/Goddard Space Flight Center

nachricht NASA detects solar flare pulses at Sun and Earth
17.11.2017 | NASA/Goddard Space Flight Center

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Carefully crafted light pulses control neuron activity

20.11.2017 | Life Sciences

SYSTEMS INTEGRATION 2018 in Switzerland focuses on building blocks for industrial digitalization

20.11.2017 | Trade Fair News

Heavy nitrogen molecules reveal planetary-scale tug-of-war

20.11.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>